The present invention broadly relates to endoscopic surgical instruments. More particularly, the invention relates to disposable endoscopic instruments having end effectors and actuation means for effecting movement of the end effectors where the actuating means include apparatus for the locking of and fixed stepped movement of the end effectors relative to each other.
The endoscopy and laparoscopy procedures have recently become widely practiced surgical procedures. The endoscopy and laparoscopy procedures involve incising through body walls (e.g., such as the abdominal wall) for examining, viewing and/or operating on the ovaries, uterus, gall bladder, bowels, appendix, etc. Typically, trocars are utilized for creating the incisions. Trocar tubes are left in place in the abdominal wall so that the endoscopic or laparoscopic surgical tools may be inserted through the tube. A camera or magnifying lens is often inserted through a relatively large diameter trocar tube (e.g. 10 mm diameter) which for the laparoscopy procedure is generally located at the navel incision, while a cutter, dissector, extractor, or other surgical instrument is inserted through a typically smaller diameter trocar tube (e.g. 5 mm diameter) for purposes of manipulating and/or cutting the internal organ. Sometimes it is desirable to have several trocar tubes in place at once in order to receive several surgical instruments. In this manner, organ or tissue may be grasped with one surgical instrument, and simultaneously may be cut or stitched with another surgical instrument; all under view of the surgeon via the camera in place in the navel trocar tube.
During a laparoscopic or endoscopic procedure, in order to properly grasp, clamp, or cut tissue or an organ, it is sometimes desirable to lock the end effectors of the endoscopic/laparoscopic tool in position relative to each other. Further, it is sometime desirable to effect movement of the end effectors toward each other in fine, stepped movements. In order to accomplish locking and stepped movement, the tools of the prior art have provided mating teeth and grooves on both the handle and lever of the tool such that movement of the teeth of the lever past the teeth of the handle effect a locking and stepping arrangement. However, such arrangements of the prior art have typically limited the practitioner to a situation where locking and stepping is the norm and torsional force is required to unlock the handle from the lever so as to release the end effectors. In addition, where disposable tools using plastic handles and levers are desirable, the double teeth and groove arrangement has proved to be unwieldy and generally unsatisfactory.
The endoscopic and laparoscopic tools of the prior art are primarily reusable stainless steel tools. Between each use of a stainless steel tool, the tool must be soaked, scrubbed, and disinfected. The usual procedure is then to dry the tool, wrap it, and put it in a steam autoclave. The tool is kept sterile until just prior to use when it is removed from the autoclave and unwrapped in the locale of the sterile field of use.
While reusable endoscopic and laparoscopic tools have functioned well for their intended purpose, the process of sterilizing the tool is problematic. Small pieces of tissue or organ often become lodged in the end effectors, and much labor is required to ensure that complete sterility is obtained and maintained. In addition, over time, sharp instruments such as a scissors get dull and must be discarded. However, prior to use of a particular instrument, the surgeon is not able to discern the state of the instrument and whether the instrument will satisfy the surgeon's requirements.
The alternative to reusable endoscopic and laparoscopic surgical tools are disposable tools. However, the complicated construction of endoscopic and laparoscopic surgical tools has typically dictated that the tools be expensive.